Flow cytometry is a diagnostic tool in order to count/visualize the amount of lymphatic cells in the body. T cells, B cells and NK cells are nearly impossible to distinguish under a microscope, therefore one must use a flow cytometer to distinguish them.

The Düsseldorf score stratifies cases using four categories, giving one point for each; bone marrow blasts ≥5%, LDH >200U/L, haemoglobin ≤9g/dL and a platelet count ≤100,000/uL. A score of 0 indicates a low risk group' 1-2 indicates an intermediate risk group and 3-4 indicates a high risk group. The cumulative 2 year survival of scores 0, 1-2 and 3-4 is 91%, 52% and 9%; and risk of AML transformation is 0%, 19% and 54% respectively.

Diagnosis is usually based on repeated complete blood counts and a bone marrow examination following observations of the symptoms. Sometimes, blood tests may not show that a person has leukemia, especially in the early stages of the disease or during remission. A lymph node biopsy can be performed to diagnose certain types of leukemia in certain situations.

Following diagnosis, blood chemistry tests can be used to determine the degree of liver and kidney damage or the effects of chemotherapy on the patient. When concerns arise about other damage due to leukemia, doctors may use an X-ray, MRI, or ultrasound. These can potentially show leukemia's effects on such body parts as bones (X-ray), the brain (MRI), or the kidneys, spleen, and liver (ultrasound). CT scans can be used to check lymph nodes in the chest, though this is uncommon.

Despite the use of these methods to diagnose whether or not a patient has leukemia, many people have not been diagnosed because many of the symptoms are vague, non-specific, and can refer to other diseases. For this reason, the American Cancer Society estimates that at least one-fifth of the people with leukemia have not yet been diagnosed.

Because the cause is unknown, no effective preventive measures can be taken.

Because the disease is rare, routine screening is not cost-effective.

Following observation of the symptoms, the patients need to get complete blood counts and a bone marrow examination. If the patient has leukemia, the morphology and immunophenotype check is needed to make sure the type of leukemia.

The morphology of the blast in BAL is not certain. The cells could display both myeloid lineage and lymphoid or undifferentiated morphology. Therefore, the diagnosis cannot based on the morphology result. The immunophenotype check is the most important basis of the diagnosis of BAL.

Before 2008, the diagnosis of BAL was based on a score system proposed by the European Group for the Immunological Classification of Leukemias (EGIL) which could differentiate from other kinds of acute leukemia. The table shows this method.

If the score of only one lineage is higher than 2, the acute leukemia could be acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL). According to the original EGIL scoring system BAL is defined when scores are over two points for both myeloid and T- or B- lymphoid lineages.

In 2008, WHO established a new and strict criteria standard for diagnosis of BAL. The presence of specific T-lymphoid antigens, cytoplasmic CD3 (cCD3), MPO and CD 19 became the most important standard for recognizing the lineage. Other B-lineage markers (CD22, CD79a, CD 10) and monocytic markers are also needed. Table 2 shows the method.

Compared with the EGIL scoring system, the current 2008 WHO criteria applied less but more specific markers to define the lineage of the blasts, and incorporated the intensity of markers expression into the diagnostic algorithm.

The diagnosis of BAL is so difficult that sometimes is misdiagnosed with AML or ALL because the morphology thus the therapy would not have a good effect.

A new method developed using data from the M.D. Anderson Cancer Center found that a haemoglobin level of 2.5 x 10/L, >0% immature myeloid cells, >10% bone marrow blasts causes a reduced overall survival. This data allows cases of CMML to be stratified into low, intermediate-1, intermediate-2 and high risk groups. These groups have median survival times of 24, 15, 8 and 5 months respectively.

The diagnosis of HCL may be suggested by abnormal results on a complete blood count (CBC), but additional testing is necessary to confirm the diagnosis. A CBC normally shows low counts for white blood cells, red blood cells, and platelets in HCL patients. However, if large numbers of hairy cells are in the blood stream, then normal or even high lymphocyte counts may be found.

On physical exam, 80–90% of patients have an enlarged spleen, which can be massive. This is less likely among patients who are diagnosed at an early stage. Peripheral lymphadenopathy (enlarged lymph nodes) is uncommon (less than 5% of patients), but abdominal lymphadenopathy is a relatively common finding on computed tomography (CT) scans.

The most important lab finding is the presence of hairy cells in the bloodstream. Hairy cells are abnormal white blood cells with hair-like projections of cytoplasm; they can be seen by examining a blood smear or bone marrow biopsy specimen. The blood film examination is done by staining the blood cells with Wright's stain and looking at them under a microscope. Hairy cells are visible in this test in about 85% of cases.

Most patients require a bone marrow biopsy for final diagnosis. The bone marrow biopsy is used both to confirm the presence of HCL and also the absence of any additional diseases, such as Splenic marginal zone lymphoma or B-cell prolymphocytic leukemia. The diagnosis can be confirmed by viewing the cells with a special stain known as TRAP (tartrate resistant acid phosphatase). More recently, DB44 testing assures more accurate results.

It is also possible to definitively diagnose hairy cell leukemia through flow cytometry on blood or bone marrow. The hairy cells are larger than normal and positive for CD19, CD20, CD22, CD11c, CD25, CD103, and FMC7. (CD103, CD22, and CD11c are strongly expressed.)

Hairy cell leukemia-variant (HCL-V), which shares some characteristics with B cell prolymphocytic leukemia (B-PLL), does not show CD25 (also called the Interleukin-2 receptor, alpha). As this is relatively new and expensive technology, its adoption by physicians is not uniform, despite the advantages of comfort, simplicity, and safety for the patient when compared to a bone marrow biopsy. The presence of additional lymphoproliferative diseases is easily checked during a flow cytometry test, where they characteristically show different results.

The differential diagnoses include: several kinds of anemia, including myelophthisis and aplastic anemia, and most kinds of blood neoplasms, including hypoplastic myelodysplastic syndrome, atypical chronic lymphocytic leukemia, B-cell prolymphocytic leukemia, or idiopathic myelofibrosis.

ANKL is treated similarly to most B-cell lymphomas. Anthracycline-containing chemotherapy regimens are commonly offered as the initial therapy. Some patients may receive a stem cell transplant.

Most patients will die 2 years after diagnosis.

Treatment with conventional immunochemotherapy is usually indicated; in younger patients, allogeneic bone marrow transplantation may be curative.

The prognosis for BAL patients is not good which is worse than ALL and AML. Medical Blood Institute reported cases of CR rate was 31.6%, with a median remission are less than 6 months

The median survival time is only 7.5 months. The life quality is also low because the immune function of patient is damaged seriously. They have to stay in hospital and need 24h care.

In another study, the results showed that young age, normal karyotype and ALL induction therapy will have a better prognosis than Ph+, adult patients. The study shows median survival of children is 139 months versus 11 months of adults, 139 months for normal karyotype patients versus 8 months for ph+ patients.

T-PLL is an extremely rare aggressive disease, and patients are not expected to live normal lifespans. Before the recent introduction of better treatments, such as alemtuzumab, the median survival time was 7.5 months after diagnosis. More recently, some patients have survived five years and more, although the median survival is still low.

Significant research into the causes, prevalence, diagnosis, treatment, and prognosis of leukemia is being performed. Hundreds of clinical trials are being planned or conducted at any given time. Studies may focus on effective means of treatment, better ways of treating the disease, improving the quality of life for patients, or appropriate care in remission or after cures.

In general, there are two types of leukemia research: clinical or translational research and basic research. Clinical/translational research focuses on studying the disease in a defined and generally immediately patient-applicable way, such as testing a new drug in patients. By contrast, basic science research studies the disease process at a distance, such as seeing whether a suspected carcinogen can cause leukemic changes in isolated cells in the laboratory or how the DNA changes inside leukemia cells as the disease progresses. The results from basic research studies are generally less immediately useful to patients with the disease.

Treatment through gene therapy is currently being pursued. One such approach used genetically modified T cells to attack cancer cells. In 2011, a year after treatment, two of the three patients with advanced chronic lymphocytic leukemia were reported to be cancer-free and in 2013, three of five subjects who had acute lymphocytic leukemia were reported to be in remission for five months to two years. Identifying stem cells that cause different types of leukaemia is also being researched.

Clonal TCR gene rearrangements for the γ and δ chains are typically found. The most frequent chromosomal abnormality is the inversion of chromosome 14, specifically inv 14(q11;q32). This is found in 80% of cases, while 10% of cases show a reciprocal translocation of chromosome 14 (t(14;14)(q11;q32)).

Treatment with dose-adjusted EPOCH with rituximab has shown promising initial results in a small series of patients (n=17), with a 100% response rate, and 100% overall survival and progression-free survival at 28 months (median follow-up).

In order to fulfill World Health Organization (WHO) criteria for AML-5, a patient must have greater than 20% blasts in the bone marrow, and of these, greater than 80% must be of the monocytic lineage. A further subclassification (M5a versus M5b) is made depending on whether the monocytic cells are predominantly monoblasts (>80%) (acute monoblastic leukemia) or a mixture of monoblasts and promonocytes (<80% blasts). Monoblasts can be distinguished by having a roughly circular nucleus, delicate lacy chromatin, and abundant, often basophilic cytoplasm. These cells may also have pseudopods. By contrast, promonocytes have a more convoluted nucleus, and their cytoplasm may contain metachromatic granules. Monoblasts are typically MPO-negative and promonocytes are MPO variable. Both monoblasts and promonocytes stain positive for non-specific esterase (NSE), however NSE may often be negative.

Immunophenotypically, M5-AML variably express myeloid (CD13, CD33) and monocytic (CD11b, CD11c) markers. Cells may aberrantly express B-cell marker CD20 and the NK marker CD56. Monoblasts may be positive for CD34.

AML-M5 is treated with intensive chemotherapy (such as anthracyclines) or with bone marrow transplantation.

The prognosis is generally poor. The "RS score" (Richter syndrome score), which is an estimate of the patient's prognosis, is based on the patient's performance status, LDH, platelet count, the size of the lymphoma tumors, and the number of prior therapies already received. Overall, the median survival is between five and eight months. Untreated, RS is invariably fatal.

The Hodgkin's lymphoma variant of Richter's carries a better prognosis than the predominant diffuse large B-cell lymphoma type, but a worse prognosis than a "de novo" case of Hodgkin's.

Of all cancers involving the same class of blood cell, 2.3% of cases are Burkitt lymphoma. Epstein-Barr virus infection is strongly correlated with this cancer.

Currently PTCL is treated similarly to B-cell lymphomas. However, in recent years, scientists have developed techniques to better recognize the different types of lymphomas, such as PTCL. It is now understood that PTCL behaves differently from B-cell lymphomas and therapies are being developed that specifically target these types of lymphoma. Currently, however, there are no therapies approved by the US Food and Drug Administration (FDA) specifically for PTCL. Anthracycline-containing chemotherapy regimens are commonly offered as the initial therapy. Some patients may receive a stem cell transplant. Novel approaches to the treatment of PTCL in the relapsed or refractory setting are under investigation.

Pralatrexate is one compound currently under investigations for the treatment of PTCL. For information please consult the US clinical trials database (http://www.clinicaltrials.gov).

Intravacular lymphoma is an aggressive cancer that is rapidly fatal without treatment, but which can respond well to combination chemotherapy, usually some combination of Rituximab, Cyclophosphamide, Adriamycin, Oncovin, and prednisone (R-CHOP).

A B-cell leukemia is any of several types of lymphoid leukemia which affect B cells.

Types include (with ICD-O code):

- 9823/3 - B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma

- 9826/3 - Acute lymphoblastic leukemia, mature B-cell type

- 9833/3 - B-cell prolymphocytic leukemia

- 9835/3-9836/3 - Precursor B lymphoblastic leukemia

- 9940/3 - Hairy cell leukemia

A case has been described as CD20+, CD22+, and CD5-.

It can also be CD5+.

Another case was described as CD45+, CD19+, CD20+, CD5+, HLA-DR+, CD10-, CD23+/-, CD38+ and FMC7-.

Acute leukemia or acute leukaemia is a family of serious medical conditions relating to an original diagnosis of leukemia. In most cases, these can be classified according to the lineage, myeloid or lymphoid, of the malignant cells that grow uncontrolled, but some are mixed and for those such an assignment is not possible.

Forms of acute leukemia include:

- Acute myeloid leukemia

- Acute erythroid leukemia

- Acute lymphoblastic leukemia

- T-cell acute lymphoblastic leukemia

- Adult T-cell leukemia/lymphoma

- (Precursor)T-lymphoblastic leukemia/lymphoma

- "Blast crisis" of chronic myelogenous leukemia

Chronic leukemia is an increase of abnormal white blood cells. It differs from acute leukemia, and is categorized as myelogenous or lymphocytic.

Chronic leukemia may refer to:

- Chronic myelogenous leukemia

- Chronic lymphocytic leukemia

- Hairy cell leukemia

B-cell prolymphocytic leukemia is a more aggressive, but still treatable, form of leukemia. The malignant B cells are larger than average. The name is commonly abbreviated B-PLL.

It can involve deletions from chromosome 11 and chromosome 13.

It has been suggested that some cases may represent a variant of mantle cell lymphoma.

It has a relatively poor prognosis.